docs: def tag_image(self, repository=None, tag=None):
          """
          Apply additional tags to the image or a new name
          >> podman tag image[:tag] target-name[:tag]
  
          :param repository: str, see constructor
          :param tag: str, see constructor
          :return: instance of PodmanImage
          """
          if not (repository or tag):
              raise ValueError("You need to specify either repository or tag.")
          r = repository or self.name
          t = tag or "latest"
          identifier = self._id or self.get_id()
          run_cmd(["podman", "tag", identifier, "%s:%s" % (r, t)])
          return PodmanImage(r, tag=t)